mutability (n.)

late 14c., "tendency to change, inconstancy," from Old French mutabilité, from Latin mutabilitas, from mutabilis "changeable" (see mutable).

It is the same!—For, be it joy or sorrow,

    The path of its departure still is free;

Man's yesterday may ne'er be like his morrow;

    Nought may endure but Mutability. 

[Shelley, from "Mutability," 1816]